I have the Fostex 3070 too, [but no manual], and come to think of it,...
the 3070 may be the only rackmount comp/limiter that Fostex ever made, [that I'm aware of].
Funny, but I've had this particular unit for a while, and up until about a minute ago, I'd have sworn it was a 3170, but alas, it verifies as a Fostex 3070. My mistake, all this time. I've even recommended the 3170 here online, and the guy probably thought I was cracked. Okay, it's the 3070.
I don't think I have the OP manual for the 3070, but just for grins, I'll go through my manual box again. I'm sure it's only a thin manual, of only a few pages.